If you do not know what you are doing.. there is two options.
1. don't do it (no fun).
2. Research alot... then do it when you are confident of success!
The VoomPCs are about as "finished" they come, but still. You need to place it some where smart, and run up cables.. perhaps make a bezzel and such like that!
The best advice I can give you... PLANING!
Plan everything in detail, before you start to buy stuff. (Unless you want to spend alot of money on stuff that will end ups as junk).